Stamp-die.



No. 667,4l5.

F. WHITE.

STAMP DIE.

(Appfieatibn filed Sept. .4, 1900.) (No Model.)

* llllHlllllllll I iiiiiiiiiiiiiillllllllllillll Patented Feb. 5, I901.

. the length of drop of the stamps.

UNITED STATES PATENT 'FFICE.

FRANK WHITE, OF NEVADA CITY, CALIFORNIA.

STAMP-DIE.

SPECIFICATION forming part of Letters Patent No. 667,415, dated February5, 1901.

Application filed September 4, 1900. Serial No. 28,930. (No model.)

To all whom it nuty concern.-

Be it known that I, FRANK WHITE, a citizen of the United States,residing at Nevada City, county of Nevada, State of California, haveinvented an Improvement in Stamp- Dies; and I hereby declare thefollowing to be a full, clear, and exact description of the same.

My invention relates to an improved die for quartz or other stampcrushing mills.

It consists of a metal base supporting and partly covered bya removablemetal cap, and of details which will be more fully set forth in thefollowing specification and drawings.

Figure l is a view of the die, the cap being shown in section. Fig. 2 isa detail view of the cap.

In the bottom of the mortar-box of stampmills it is customary to placeheavy dies or metal blocks to receive the impact of the stamp,which isalternately raised and dropped upon the material between it and the die.These dies are ordinarily seven or eight inches high and about teninches in diameter and weigh upwards of two hundred pounds. The constantdropping of the stamps upon the hard rock interposed between thesecrushing-surfaces rapidly cups and wears away and chips the face of thedie. This wear is seldom or never evenly distributed, and the crushingforce of the mill is consequently impaired. The expense of replacementof the dies is too great to permit of frequent change, and accordingly adie is continued in use until often it is less than half its originalheight, with the resulting variation in In this case the stamps andtheir connections of cams, &c., all require readjustment, or theirwearing parts will otherwise be subjected to unusual and destructivestrain. Furthermore, these solid dies must be made of metal of equalquality. This is usually steel or a very hard form of iron and is quiteexpensive compared with the ordinary cast-iron. Much costly material isthereby thrown to Waste when a die is finally discarded.

in my invention I make the die of two parts. The base A, which is thebulkier portion, may be made of cheap iron, as no wear is to come uponit.

B is a cap fitting upon A and is made of steel or hard iron. The top 5of this cap is the crushing-surface of the die.

The upright portion 2 of A is cylindrical in form. About the base of.2is a flat annular shoulder 3, upon which the edge 4 of B is adapted torest.

.Upon the top of A a thin layer of quartz sand is placed before puttingon the cap. This sand evens olf 'any inequalities in the contactingsurfaces of the castings, soon pounds or packs solidly, preventsbreakage of the parts or wear of the part A, and offers a firm supportfor the stamp to fall upon. The parts are all held together by theirweight, their shape, and by the suction of the water in which theyarecontinually immersed.

With my device I am able to offer a practical cheap renewable die, forwhich there has long'been a demand. With this die it is intended torenew the crushing-surface or cap B frequently-say every thirty daysasthat has been found to be about the length of time during which bestresults can be accomplished.

It has been found that the extra amount of rock that can be treated byhaving new crushing-faces is more than sufficient to compensate for lossof iron discarded.

The heavier part or base of the die Will not need renewing in years withordinary care. The consequent economy in cost to the mill owner andincreased efficiency of the mill becomes plainly apparent. Furthermore,as many mills are situated in places difficult of access, whereeverything'has to be packed in by mules or similar means, the cost offreighting is a very considerable item. Hence as dies are continuallyneeded for the old ones discarded the difference in the item of freightalone between a die of the ordinary type and mine is a very considerablefactor in favor of the latter and in view of the foregoing.

No special form of mortar or mill is necessary for my dies.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. The combination with a die having an upper extension, of a capcapable of being dropped over said extension, the flange of said caphaving such vertical depth that it incloses the said extension and formsa long bearing to properly seat the cap.

2. A stamp-die comprising a metal base having a cylindrical extensionand a flat annular shoulder about the base of the extension, and acylindrical cap of harder material adapted to fit removably over theextension on the base, and the lower edges of the cap bearing, upon thesaid annular shoulder.

3. In a stamp-die, the combination of a solid metal base,a removablemetal cap adapted to fit and to be retained solidly upon this base, anda packing interposed between the inner face of the cap, and the top ofthe base whereby the unevennesses of these two surfaces are compensated,and the parts made to bear solidly upon each other.

4. In a stamp-die, the combination of a metal base having a centralsolid extension, and a hollow metal cap, fitting upon and removablefrom, said extension, and a packing consisting of a thin layer of sandor finelyground rook interposed between the top of the extension and theinterior of the cap.

In witness whereof I have hereunto set my hand.

FRANK WHITE.

Witnesses:

J AS. J. OTT, JNo. WERRY.

